Hydraulically operated leather processing machine



June 6, 1950 $M|TH 2,510,913

HYDRAULICALLY OPERATED LEATHER PROCESSING MACHINE Filed May 1, 1948 2 Sheets-Sheet l INVENTOR. Jay M .fm/z fi Patented June 6, 1950 2,5itt913 FFlCE HYDEAULICALLY OPERATED LEATHER PROCESSING MACHINE Jay M. Smith, San Francisco, Calif.

Application May 1, 1948, Serial No. 24,577

(01. fill--42) 1 Claim.

My invention relates generally to machines for processing leather, especially means for operating devices functioning according to a cyclic movement. There are various different kinds of leather processing machines in which rotary devices such as rollers or cutters have to be moved into and out of engagement with a leather sheet. This cyclic movement is usually accomplished by some sort of a mechanical jaw clutch individually controlled by an operator. The operation of the machine depends for its effectiveness largely upon the attentiveness and skill 01" the operator and is often somewhat marred by the shock and strain imposed upon the mechanism and upon the material being treated by the abrupt engagement of the clutch.

It is therefore an object of my invention to provide a leather processing machine which is hydraulically operated and is smoother and more uniform in its operation and results.

Another object of my invention is to provide a leather processing machine in which the cycle is automatically established as to its length.

Another object of my invention is to provide an improved leather processing machine.

A still further object of the invention is to provide a hydraulically operated leather processing machine which is improved yet still is of the general type universally established and accepted.

Other objects of my invention together with the foregoing are attained in the embodiment thereof described in the accompanying description and illustrated in the accompanying drawings, in which Figure 1 is a side elevation of a typical leather processing machine with the invention embodied therein, certain parts being illustrated diagrammatically.

Figure 2 is a front elevation of a portion of the machine illustrated in Figure 1', parts being broken away to reduce the size of the figure.

Figure 3 is a cross-section to an enlarged scale, the plane of section being indicated by the line 3--3 of Figure 2.

In its preferred form, the hydraulically operated leather processing machine of my invention includes a main frame having a pair of bell-crank levers pivoted on it, usually at the opposite ends. These levers carry some sort of leather processing roll and are joined by a pair of links to a pair of cranks mounted on a drive shaft extending along the length of the main frame. The links have two dead-center positions with respect to the cranks corresponding to the two ends of the cyclic position of the leather processing roll. On the drive shaft is mounted a pinion engaged by a rack actuated by a hydraulic piston. A cylinder encloses the piston and is of a length to stop the piston automatically at the opposite ends of its stroke to correspond with the two dead-center positions of the links.

While the hydraulically operated leather processing machine of my invention is capable of embodiment in many difierent forms depending upon the particular leather process to be accomplished, it has successfully been incorporated as shown herein in a machine in which there is a main bed roll 6 and certain auxiliary prooessing rolls 1, 8 and 9 respectively which are dlagrammatic representations of operating mechanisms. The roll 6 is mounted on a shaft H ex tending across the main frame l2 of the machine. At its opposite ends, it being understood that the machine is symmetrical on both sides, the shaft H is carried in journals [3 mounted in bell crank levers l4. Auxiliary adjusting mechanism 16 governs the particular positioning of the roll 6 with respect to the levers M.

The bell-crank levers are suitably mounted in the main frame l2 by fulcrum pivots i8 disposed between the ends of the levers. Each of the levers is also provided with a pivot connection l9 to which is connected one end of a link 2!. Adjustments 22 and 23 are provided for setting the precise length of the link. The opposite end of the link 2| is provided with a pivot connection 24 to one of a pair of main cranks 26.

Since the machine is symmetrical on both sides of its center line, the two main cranks 26 are located on a driving rock shaft 21 which extends across the main frame l2 and is carried in suitable journals 28 thereon. The arrangement of the cranks 26, the links 2i and the levers I4 is such that the link 2| occupies one deadcenter position as shown by the full line showing in Figure 1 when the roller 6 is in one of its extreme cyclic positions, and occupies another dead-center position as illustrated by the broken lines in Figure 1 when the roller t is in the other of its extreme cyclic positions. The dead center positions of the link with respect to the crank are situated approximately one hundred sixty degrees apart in the present instance, although that angular measurement varies between installations.

In order to drive the main drive shaft 21, I mount on it at a convenient location and especially as shown in Figure 3 a pinion gear 3| having suitable keys 32 and preferably split so that within the cylinder and is fast on the piston rod 36 so that the piston and the rack operate in unison. Preferably, the length of the cylinder 38 is made such that the piston 39 just contacts the ends of the cylinder to complete its stroke asthe crank 26 arrives in its dead-center positions. The stroke of the piston 39, therefore, corresponds with the two cyclic terminal positions of the roll 6 so that when the piston arrives at the ends of its stroke, the roll is accurately posi tioned. 7,

In order to drive the piston39, the cylinder 38 is provided with a pair of hydraulic conduits 4! and 42 leading to a standard hydraulic valve 43 provided with an oil inlet 44 and an oil outlet 46. A handle 41 convenientlydisposed for the operator is effective to provide pressure fluid on either side of the piston 39; and to exhaust spent fluid from the other side of the piston.

-With this arrangement, the operator has merelyto manipulate the handle 41 and the machine is supplied with hydraulic pressure fluid to begin its cycle. Since this-hydraulic actuation begins relatively gradually and is a firm although smooth propelling medium, the roll 6 is smoothly brought away from one of its extreme positions. While the operator by manipulating the valve 41 can stop the piston motion in midstroke, normally he does not have to concern himself with the valve after once having positioned it for starting since the piston 39 continues under hydraulic pressure until it abuts the end of the cylinder 38. The relationship is such that in this piston position, the roll 6 is in its extreme position because the link 2| is in one of its deadcenter positions with respect to the crank 26. A reverse movement of the valve 41 reverses the hydraulic operation and drives the piston 39 to stop at the other end of the cylinder and consequently to stop the roll I in its other extreme cyclic position.

I claim:

A hydraulically operated leather processing machine comprising a frame, a pair of bell-crank levers pivotally mounted on said frame, a bed roll journaled in said bell-crank levers, a driving rock shaft mounted in said frame, cranks on the ends of said rock shaft, links connecting said cranks and said levers and adapted to occupy two dead-center positions not diametrically opposed about the axis of said rock shaft, a pinion on said drive shaft, a rack engaging said pinion, a piston joined to said rack in fixed relationlthereto, a hydraulic cylinder operatively enclosing said piston, a hydraulic fluid system connected to said cylinder, and means for stopping said piston in two extreme positions so located as todrive said cranks to extreme positions corresponding to said dead-center positions.

JAY M. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 513,601 Teal Jan. 30, 1894 1,131,756 Wayland Mar. 16, 1915 1,214,852 Wayland Feb. 6, 1917 1,763,058 Lewis June 10, 1930 2,054,443 Pierson Sept. 15, 1936 2,433,352 Edgar Dec. 30, 1947 

